1. Field of the Invention
The present invention relates to a method of applying paint to a workpiece wherein the painting can efficiently be carried out with electrostatic spraying.
2. Description of Related Art
There have heretofore been used various types of painting apparatuses having color changeover functions with a view toward carrying out efficient and speedy painting work using electrically conductive coatings or paints where the colors differ one to the other. One of such painting apparatuses is disclosed in Japanese Laid-Open Patent Publication No. 2-2885, for example. More specifically, the disclosure comprises a paint feed source for feeding a plurality of different paints, first and second paint reservoirs selectively supplied with paints through electrically insulated paint feed means, a first cleaning means for cleaning the paint feed means after the paints are fed to the first and second paint reservoirs, a second cleaning means for cleaning the other of both reservoirs while the paints are being delivered from one of them, a third cleaning means for cleaning paint delivery means used to deliver the paints to a coater, i.e., a spray gun from the respective first and second paint reservoirs, etc.
In the above-described conventional apparatus, the paints are alternately supplied to the first and second paint reservoirs from the paint feed source. In addition, the electrically-insulated paint feed means, the first and second paint reservoirs and the paint delivery means are cleaned by the first through third cleaning means each time the paints are delivered from the respective first and second paint reservoirs.
However, the above cleaning work is carried out even when the same paint is supplied to the first and second paint reservoirs, thereby causing a problem that usable and expensive paint is wastefully discharged.
Further, the apparatus has changeover valves for selecting either one of two discharges of the paint from the first and second paint reservoirs, and the like. However, there are parts of the apparatus, which are difficult to clean, for example the changeover valves or the like at the time of the cleaning work, so that the cleaning liquid is required in large quantities.